Electrical relay



I June 2, 1931.

. P. H. DOWLI'NG ELECTRICAL RELAY Filed June so, 1930 2 Sheets-Sheet 2 INVENTOR. Z

ATTORNEY Patented June 2, 1931 UNITED STATES PATENT OFFICE PHILIP H. BOWLING, OF SWISSVALE, PENNSYLVANIA, .ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SW'ISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA ELECTRICAL RELAY Application filed June 30,

My invention relates to electrical relays of the type comprising an input winding and a movable armature controlled in accordance with the current supplied to such winding. More particularly my present invention relates to electrical relays of the type described in which the armature is controlled by magnetic flux which is at times shunted away from the armature by means responsive to the input current. In the particular embodiment herein disclosed, the armature is urged in opposite directions by fluxes in two separate cores, and the fluxes in these cores are controlled by input current in such manner that the flux in one core is increased and the flux in the other core is decreased in response to a given change in the input current. Another feature of my invention is the provision of electrical relays of the type described in which comparatively small changes in the input current produce comparatively large changes in the torque applied to the armature. Relays embodying my invention, therefore, perform the functions both of am- 5 plifiers and relays.

I will describe several forms of electrical relays embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a top plan view, partially diagrammatic, illustrating one form of electrical relay embodying my invention. Fig. 2 is a view showing in front elevation, the relay illustrated in Fig. 1. Fig. 3 is a detail side view of the core A of Figs. 1 and 2 showing its relation to the armature E. Fig. 4 is a detail view similar to Fig. 3 showing the core B and its relation to the armature E. Figs. 5, 6, 7 and 8 are views showing various modifications of portions of the relay shown in Figs. 1-4, inclusive, and also embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1 and 2, the relay, designated in general by the reference character R, comprises four magnetizable cores A, B, C and D, and a movable magnetizable armature E. The core A is provided with sition in the bridging member 20 of core 0.

1930. Serial No. 464,763.

a main arm 1 having at one end an upstand ing leg 2 terminating in a pole face 3. On the other end of the arm 1 is an extension 4 passing under the armature E and carrying an upstanding leg 5 terminating in a pole face 6. As best shown in Fig. 3, the pole face 3 is adjacent one end of the armature E and the pole face 6 is adjacent the other end of this armature and on the opposite side thereof. The core B comprises a main arm 7 having a downwardly projecting leg 8 terminating in a pole face 9 confronting the pole face 3 of core A but on the opposite side of armature E. The other end of arm 7 is provided with an extension 10 carrying a'downwardly projecting leg 11 terminating in a pole face 12 confronting pole face 6 of core A but on the opposite side of armature E. The relation of core B to the armature E is best shown in Fig. 4. The armature E is pivotally mounted, by means forming no part of my present invention, and not shown in the drawing, for swinging motion about the axis E It will therefore be plain that the armature may swing into engagement with the pole faces 3 and 6 of core A or into engagement with the pole faces 9 and 12 of core B, depending upon the fluxes supplied to these cores.

The core C, as here shown, is of the well known shell type comprising two magnetic paths having a bridging member in common and is located adjacent the main arm 1 of core A. The core D is similar to core C and is located adjacent the main arm 7 of core B.

Primary flux is supplied in the relay R by means of local windings supplied with periodic current from a suitable source, here shown as an alternating current generator G. For this purpose, local windings L and L link the core C and the main arm 1 of core A and are connected in series with generator G in such manner that the fluxes created by currents in windings L and L are in oppo- In similar manner, local windings L and L link the core D and the main arm 7 of core B and are connected in series across generator G in parallel with windings L and L in such manner that the flux created by current thus supplied to windings L and L are in opposition in the bridging member 21 of core D. With this arrangement, the fluxes supplied by cores A and B urge the armature in opposite directions and the armature will respond to the difference between these fluxes. V

V The bridging member 20 of core- C is provided with a bias winding H and the bridging member 21 of core D is provided with a bias winding H windings H and H being connected in series with a suitable source of current, here shown as a battery 22. The fluxes, here assumed to be uni-directional, supplied to the cores and D by currents in the bias windings H and H adjust these cores to proper points on their characteristic curves, and regulate tothe desired value the amountof the primary fluxes delivered by windings L ,.L L and L which thread the cores A and B. I For controlling the relay R, I provide two input windings vK and K located respectively on the bridging members 20 and 21 of cores G and D. The input windings K and K are included in an input circuit in such manner that a-current suppliedto such circuit .aids the flux created by one bias winding and opposes the flux created by the other bias winding. The inputcircuit may be supplied with current from any suitable control source andthis currentis preferably though not necessarily alternating current of afrequency less than that of the source G. The operation of therelay is as follows: When current of normal value, usually Zero, is being supplied to the input circuit, the parts are balanced so that the torques exerted on armature E are equal. If current of one polarity is now supplied to the input circuit including windings K and K the biasing flux in one of the cores C or D will be increased andthe biasing flux in the other core will be decreased. Assuming that the current supplied to the input circuit is of such polarity as to aid the biasing flux in core C, and to oppose the biasing flux in core D,

r the effect will be to decrease the permeability of core C and to increase the permeability of core D. The primary fluxdelivered by the windings L L L and L remain substantially constant, but since the permeability of core .0 has now been decreasecha greater proportlon of the flux from wlndings L and L will thread core A. Similarly, since the permeability of core D has been increased, a smaller proportion of theprimary flux from windings L and L will thread core B. The net result of these changes in flux vfrom cores A and B is to draw the armature E toward pole faces 3 and 6 of core A.

1 If current of the opposite polarity is supplied to the input circuit the effectis just the oppositeto that described above and the armature E will then be drawn into engage- ,a fixed contact 17* whenthe armatureo'ccu ment with pole faces 9 and 12 of core B. It will be apparent that when alternating current'is supplied to the input circuit including windings K and K the armature E will be oscillated at the frequency of such current. Furthermore, it is apparent that-a comparatively small change in the input circuit may be made to produce a comparatively large change in the primary fluxes delivered to cores A and B so that theapparatus operates as an amplifier as well as a relay;

It should be pointed out that when the armature E engages the pole face of one core A or B, the reluctance of this core is considerably lower thanwhen the armature swings to the opposite vposition. It follows that when the armature isbeing drawn toward the pole faces of one of these cores, the flux in the core which it is approaching is strengthened and the flux in the other core is weakened by the changes in the reluctance of the two cores due to the change in armature position. Due to this inherent stability of the structure, the armature will always assume a position in engagement with one of the cores A or B and will notnormally occupy the intermediate positionin which itis shown in the drawings.

The change in reluctance of the'core's A and B due to changes in armature position described above may, under some conditions, be so large as to interfere with the sensitivity of the relay. I therefore provide asnubbing winding 14, on the leg 11 of core B, and a second'snubbingwinding 15-on the leg of core A. The circuits for these snubbing windings 14: and 15 are controlledby contacts operated by the armature E. Thus when the armature is-swunginto engagement with core A, contact 16 16 .is c'losed, thereby completing a low resistance circuit for the snubbing winding l5on core A and tending to reduce the flux through this core. Similarly, when the armature E moves into engagement :with the pole faces of core B, contact 16-.16 is closed, completing a circuit for the snubbing winding 14 on core B and tending to reduce the flux through this core. By properly proportioning the parts, the

snubbing action caused by windingslA and" 15 may be designed to give the proper relation between the desired stability of operation and the required sensitivity- The armature E control suitable'electrical contacts in any desired manner. As ,here shown, the armature carries a movable contact 17 arranged toengagea fixed contact 17 when the armature occupies one extreme position and pies the other extreme position.

Relays embodying my inventionare particularly suitable for, though in no way limited to, use in train control systems of the coded type in which the rails are supplied with train controlling current periodi-- cally varied at different frequencies. In systems of this character, the input circuit of the relay B would be supplied with alternating current of the same frequency as such variations in the trackway current, and the relay will then respond, as will be described hereinafter, to operate this armature at the same frequency as the current supplied to this input circuit. The armature will then control apparatus which is selectively responsive to the frequency of the input current in any suitable manner. One form of train control system operating in the manner described is disclosed in a copending application for Letters Patent of the United States, Serial No. 166,407, filed February 7, 1927, by P. N. Bossart, for railway traflic controlling apparatus. \Vith the ap paratus there disclosed, a relay embodying my invention could have its input circuit receiving energy from the secondary of transformer Q and having its contacts 1717- and 17l7 controlling the primary of transformer T, as shown in the Bossart application.

If the input current is unidirectional current, the relay may be adjusted so that for normal values of this current, usually zero, the flux through one core, for example, core A, predominates over the flux in the other core so that the armature is held in one extreme position. The parts are then so arranged that' when current is supplied to the input circuit the flux through core A is decreased and the flux through core B is increased. With this arrangement the armature will occupy one position when the input current is below a given value, and the other position when the input current is above this value. If the input current is pulsating, therefore, the armature will swing to and fro at the frequency of such pulsation.

Under some conditions, the sensitivity of the relay may be improved by employing the construction illustrated in Fig. 5. In this modification, the local windings L and L embrace only the core C and a tuned winding T located on core A is connected in series with these windings and the generator G. In similar manner,'local windings L and L are located wholly upon core D and a tuning winding T located on core B is connected in series with windings L and L and the generator G. A condenser 31 is connected across the terminals of tuning winding T, and a condenser 32 is connected across the tuning winding T It will be plain that the windings U, L and T connected in series supply flux to the cores C and A in a manner similar to the local windings L and L of Fig. 1 which embrace both these cores. Furthermore, the distribution of flux between the cores C and A will be controlled by the input circuit in the same manner as described hereinbefore. Similarly, the distribution of flux between cores B and D is also controlled by the input circuit as in Fig. 1. With the construction shown in Fig. 5, however, each tuning coil T with its associated condenser and the corresponding local windings constitute a complex tuned circuit, a portion of the reactan-ce of which varies with the position of the relay armature. With a given state of the input circuit, the electromotive force across either tuning winding T may be made to depend quite critically upon the position of the armature. The fluxes in cores A and B are substantially proportional to the electromotive forces across windings T and T respectively, and the force applied to the armature due to these fluxes is substantially proportional to the square of such fluxes. It follows that by properly proportioning the parts, the force exerted on the armature by the flux through either of cores A or B may be made to depend critically upon the position of the armature. The condensers 31 and 32 may therefore be so proportioned that although the armature be held strongly in either extreme position, a small displacement of the armature will cause it to move smartly to the other extreme position where it will again be strongly held.

I have discovered that with the parts constructed as shown in Fig. 5, the relay may be operated in response to input currents substantially smaller than those required for the relay shown in Figs. 1 to 4, inclusive, without affecting the torque available for holding the armature in its extreme positions. I have further discovered that by properly proportioning the parts, the effect of the condensers may be so magnified as to cause the relay to produce self-sustained oscillations of its armature with zero input. For example, with. a generator G delivering alternating current of commercial frequency of the order of 100 to 500 cycles per second, I have constructed a relay, as shown in Fig. which will oscillate at frequencies which may be adjusted from the order of two oscil lations per second to frequencies of approximately 50 oscillations per second.

The two condensers 31 and 32 of Fig. 5 may be replaced by a single condenser with the arrangement shown in Fig. 6. This view is a Wiring diagram showing a single cdhdenser 33 connected across windings T and T The remaining portions of the device are assumed to be similar to those illustrated in Fig. 5.

In the modification shown in Fig. 7, the local windings L L L and L are disposed and connected in precisely the same way as in Fig. 1, but cores A and B are provided with tuning windings T and T respectively. Condenser 31 is connected across winding T The operation of the modification shown in 'Fig. 7 is identical with that described above electromotive forces induced in these wind- "corefmeans for at times supplying vindings i land 15, described in connection with Fig. 1, could be employed with any of the relays illustrated in Figs. 5 to 8, inclusive. 1 make no claim, in the present application,

' to two magnetic amplifiers arranged in pushpull relation, as a combination of general application, this combination being disclosed and claimed in a copending application, Serial No. 462,994, filed June 23, 1930, by A. J. Sorensen and P.'H. Dowling, for electrical translating apparatus.

Although I have herein shown and de scribed only a few forms of electrical relays embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the ap pended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. An electrical relay comprising a first flux to said core, a movable armature controlled by the flux in said core,'a second core for shunting fiux away from said first core, and a winding on said second coreoperating when supplied with currentto vary the shunting effect of said second core.

2. An. electrical relay comprising a first core, means for at times supplying flux to said core, a movable armature controlled by the flux in said core, a second core for shunting flux away from said first core, and a winding on said second core operating when supplied with current to vary the permeability of said second core to flux supplied by said means.

8. An electrical relay comprising two magnetizable cores, a movable armature controlled by the fiux in oneof said cores, a winding linking both said cores and operating when supplied with. current to create flux which.

divides between such cores, and means for at times varying the distribution of flux between said cores to control said armature.

4. An electrical relay comprising two magnetizable cores, amovable armature controlled by the flux in one of said cores, a local winding linking both said cores and operating when supplied with current to create flux which divides between such cores, and a second winding'linking the other said core and operating when supplied with current to vary the permeability of such other core to flux from said local winding;

5. An electrical relay comprising two magetizable cores, a movable armature controlled by the fiux in one of said cor-es, a local-- winding linking both said cores and operating when supplied with current to create flux which divides between such cores, a second winding on the other said core constantly supplied with current, and a third winding linking said other core and operating when supplied with current to vary the resultant flux created by current in said second winding to control the permeability of such other core to flux from said winding.

6. An electrical relay comprising a, first magnetizable core having two magnetic paths with a portion of said core in common to such paths, a second magnetizable core, a movable armature controlled by flux in said second" core, a first and a second winding linking said two paths respectively of said first core and both linking said second core, means for supplying alternating current to said first and second windings in such manner that the fiuxes created thereby in said first core are in opposition in said common portion, and a third winding linking said common portion and operating when supplied with currentto vary the permeability of said first core to fiux from said first and second windings.

7. An electrical relay comprising two local windings supplied with current, a movable armature controlled by flux created by current in said local windings, two magnetiz able cores linking said two windings respectively, and an input circuit operating when supplied with current to increase the permeability of one said core while decreasing the permeability of the other core.

8. An electrical relay comprising a first and a second core, a movable armature controlled by the difierence between the fluxes in said first and second cores, two local windi-ngs constantly supplied with current and linking said first and second cores respectively, a third core linking one of said local windings, a fourth core linking the other local winding, and an input circuit operating when supplied with current to increase the permeability of said third core while decreasing the permeability of said fourth core.

9. An electrical relay comprising a first and a second cor-e, a movable armature controlled by the difierence between the fluxes in of both said third and fourth cores in such manner that the flux'in said first core is in-* creased while the flux in said second core is decreased.

10. An electrical relay comprising two magnetizable cores, a movable armature controlled by the flux in one of said cores, a winding linking both said cores and operating when supplied with current to create flux which divides between such cores, means for at times varying the distribution of flu; between said cores to control. said armature, and means responsive to the position of said armature for at times varying the permeability of one of said cores.

11. An electrical relay comprising two magnetizable cores, a movable armature controlled by the flux in one of said cores, a winding linking both said cores and operating when supplied with current to create flux which divides between such cores, means for at times varying the distribution of flux between said cores to control said armature, and means controlled by said armature for governing the effective reluctance of said one core.

12. An electrical relay comprising two magnetizable cores, a movable armature con trolled by the flux in one of said cores, a winding linking both said cores and operating when supplied with current to create flux which divides between such cores, means for at times varying the distribution of flux between said cores to control said armature, a second winding on said one core, and means controlled by said armature for at times short-circuiting said second winding to decrease the torque exerted upon the armature by flux from said one core.

13. An electrical relay comprising a first and a second core, a movable armature controlled by the difference between the fluxes in said first and second cores, two local windings constantly supplied with current and linking said first and second cores respectively, a third core linking one of said local windings, a fourth core linking the other local winding, an input circuit operating when supplied wth current to increase the perme ability of said fourth core, two snubbing windings located on said first and second cores, respectively, and circuits for said snubbing windings controlled by said armature.

14. An electrical relay comprising a pivotally supported magnetizable armature, a first magnetizable core having two pole faces adjacent opposite sides of said armature on opposite sides of its pivotal support, a second magnetizable core having two pole faces confronting the pole faces of said first core but on opposite sides of said armature, a third and a fourth core, a first local winding linking said first and third cores, a second local winding linking said second and fourth cores, means for supplying said local windings with current, and an input circuit arranged when supplied with current to decrease the perineability of said third core while increasing the permeability of said fourth core.

15. In combination, two open magnetizable cores each having two pole faces, a )li' oted armature arranged to swing toward the pole faces of one or the other of said cores in accordance with the relative value of the fluxes in such cores, a third core, means for creating flux which divides between said third core and one of said open cores, a fourth core, means for creating flux which divides between said fourth core and the other said open core, and an input circuit arranged when supplied *ith current to increase the permeaability of said third core but to decrease the permeability of said fourth core.

16. In combination, two open magnetizable cores each having two pole faces, a piv oted armature having one end located between a pole face of one core and a pole face of the other core and having its other end located between the remaining pole faces of said cores in such manner that the armature is swung toward one or the other of said cores in accordance with the relative value of the fluxes in such open cores, two local windings linking said two open cores respectively, means for supplying current to said local windings, a third core linking one said local winding, a fourth core linking the other said local winding, two bias windings located on said third and fourth cores respective ly, means for supplying said bias winding with current to adjust the permeabilities of said third and fourth cores to values at which the fluxes created by current in said local windings are normally balanced in their effect upon said armature when the armature occupies its middle position, two input windings located on said third and fourth cores respectively, and an input circuit in cluding both said input windings and operating when supplied with current to aid the flux created by one said bias winding but to oppose the flux created by the other said bias winding.

17. In combination, two open magnetizable cores each having two pole faces, a pivoted armature having one end located between a pole face of one core and a pole face of the other core and having its other end located between the remaining pole faces of said cores in such manner that the armature is swung toward one or the other of said cores in accordance with the relative value of the fluxes in such open cores, two local windings linking said two open cores respectively, means for supplying current to said local windings, a third core linking one said local winding, a fourth core linking the other said local winding, two bias windings located on said third and fourth cores respectively, means for supplying said bias winding with current to adjust the permeabilities of said third and fourth cores to values at which the fluxes created by current in said local windings are normally balanced in their effect upon said armature when the. armature occupies its middle position, two input windings located on said third and fourth cores respectively, and an input circuit at times supplied with alternating current and including. both said input windin-gsand operating during half cycles of one polarity of such alternating current to aid the flux createdby one said bias winding. but to oppose the fiuX created by the other said bias winding, said input circuit operating during half cycles of the other polarity of such alternating current to aid the flux created by said other bias winding and to oppose the flux created by said one bias winding.

18. An electrical relay comprising two magnetizable cores, a movable armature controlled by the liux in one of said cores, a circuit operating when supplied with current to create flux in both said CQi'cS, and a wind ing linking the other said core and operating when supplied with current to vary the distribution of flux from said circuit between said two cores.

19. An electrical relay comprising two magnetizable cores, a movable armature controlled by thefiux in one of said cores, a circuit operating when supplied with current to create fiuz; in both said cores, a condenser connected across at least a portion of said circuit, and a winding linking the other said core and operating when supplied with current to vary the distribution of flux from said circuit between said two cores.

20. An electrical relay comprising two niagnetizable cores, a movable armature controlled by the flux in oneof said cores, a circuit operating when supplied with current to create flux in both said cores, tuning means associated with said circuit for varying the flux in said one core in response to the position of said armature, and a winding linking the other said core and operating when supplied with current to vary the distribution of flux from said circuit between said two cores. 5

21. An electrical relay comprising two magnetizable cores, a movable armature controlled by the fiux in one of said cores, a circuit operatin when supplied with current to create flux in both said cores, a first winding on said one core, a condenser connected across said first winding, and a second winding linking the other said core and operating when supplied with current to vary the distribution of flux from said circuit between said two cores. 7

A 22. An electrical relay comprising ,two Inagnetizable cores, a movable armature controlled by the flux in one of said cores, a local winding linking both said cores, a second winding on said one core, means for supplying said local winding andsaidsecond windcore, tuning means associated with said sec-- ond windin and a third windin inductivel :37 v 2: r related with the other sa d core and operating when supplied with current to vary the distribution c-ffiui; between saidtwo cores.

2%. An electrical relay comprising a first and a second core, amovable armature controlled by the'difference between thefluxes in said first and second cores, t wolocal windings constantly supplied with current and linking said first and second cores respectively, a third core linking one of said local windings, a fourth core linking the other local winding, a third winding inductively related with said first core, a fourth winding inductively related with said second'core, means including a condenserfor connecting said third and fourth windings together, and an input circuit operating when supplied with current to increasethe permeability: of said third core while decreasing the pervmeability of said fourth core.

In testimony whereof Iafiix my signature.

PHILIP ii. BOWLING.

mg with current to produce fiuX in both said 

